What would that union do? Use violence or the law to force employers not to automate programming? That would be a net negative for society. One thing I like about nerd culture, is that the kind of self deception needed to convince oneself that a union is good for everyone, is absent from the nerd community. Amongst socially better adjusted people, the in group instinct is stronger, and even smart people convince themselves the the supply of labor in their industry has to be restricted, (for the good of all, of course).